Embodiments of the inventive subject matter generally relate to power systems and more specifically to a power system and a method for reducing a high frequency circulating harmonic current flowing between a plurality of converters of the power system.
Power systems, such as solar based power systems, wind based power systems, and the like, can include a plurality of converters connected in parallel to each other. The power system typically includes inductors and capacitors coupled to the converters. High frequency circulating harmonic current can flow between the converters due to a low value of impedance of a resonant path that is formed by the capacitors and inductors. Stress on power semiconductor devices in the converters and cables can be increased from this circulating current.
Currently, different techniques have been employed to limit the circulating current between the multiple converters. A current limiting reactor having a high inductance value can be connected to each converter for limiting the circulating current. The use of the current limiting reactors, however, can increase the cost and footprint of the power system. A high speed communication network has been used to communicatively couple the multiple converters to each other to limit the circulating current. The use of the high speed communication network can compromise the reliability of the power system.